Basket-style carriers are commonly employed to package beverage bottles. They include a separate cell for each bottle, from which the bottles can be readily removed, and a center handle partition. The carriers are fabricated from a blank which is folded and glued into collapsed carrier form, after which the collapsed carrier is erected. In one design the bottom panel is integrally formed so that when the collapsed carrier is erected bottles may be inserted down onto the bottom panel through the open cells. In another design the bottom panel is formed by connecting bottom panel flaps after the bottles have been inserted into the cells. The bottles are commonly inserted in this latter design by moving an opened carrier down over a group of stationary bottles, although the bottles may also be inserted by moving them down into the opened carrier.
In either case, to insert the bottles prior to forming the bottom panel the collapsed carrier must not only be opened to a square condition so as to permit entry of the bottles into the appropriate cells, but must be maintained in this condition until relative movement of the bottles into the carrier progresses to the point where the bottles themselves are capable of holding the carrier open. This is necessary because the end panels of a typical basket-style carrier include a vertical fold line aligned with the handle panel, which allows the end panels to be folded into collapsed condition. These end panel segments tend to fold back toward their original position after being initially opened, which misaligns the cells and bottles. To counter this tendency, elements of the packaging machine have been designed to initially maintain the carrier in open condition until the bottles are inserted to the point where they are able to hold the carrier open. This complicates the design of the packaging machine, however, and can be a limitation on the speed of the machine.
Another problem encountered in basket-style carriers is the difficulty of providing a tight fit between articles and the walls of the cell in which they are contained. When inserting articles into a carrier whose bottom panel has already been formed, the article-receiving cells must be large enough to readily permit entry of the articles. This necessarily results in a less than tight fit between the articles and the carrier. Although the ability to form the bottom panel after the articles have been inserted at least theoretically permits the bottom and side panels to be more tightly drawn about the articles, it is quite difficult to create a tight fit between the end panels and the articles.
It would be highly desirable to be able to maintain the erected carrier in open condition by means other than by packaging machine elements without complicating the carrier design or making it more expensive. It would also be desirable to be able to create a tight fit between the articles and all the panels of a basket-style carrier.